Todennäköisyyssuhde

todennäköisyyssuhde is a term in Finnish statistics and probability theory that translates to "likelihood ratio." It is a measure used to compare the plausibility of two competing hypotheses or models given a set of observed data. Specifically, the likelihood ratio is the ratio of the likelihood of the data under one hypothesis to the likelihood of the data under another hypothesis.

In simpler terms, it tells us how much more likely the observed data is under one scenario compared to another. A likelihood ratio greater than 1 suggests that the data is more consistent with the hypothesis in the numerator, while a ratio less than 1 indicates it's more consistent with the hypothesis in the denominator. A ratio of 1 means the data supports both hypotheses equally.

The concept of the likelihood ratio is fundamental in statistical inference, particularly in hypothesis testing and model selection. It forms the basis for many statistical tests, such as the likelihood ratio test, which is used to determine whether a particular model is a significantly better fit for the data than a simpler, nested model. It plays a crucial role in understanding how evidence from data updates our beliefs about different possibilities.